The priest was Bernadito Auza, a Filipino archbishop who is also the permanent observer of the Holy See to the United Nations — and he was not joking.

Pope Francis speaks with fellow Argentine Ismael Alba.AP

That day launched Alba and his devoutly Catholic family on a religious and culinary adventure, culminating with him and his mother-in-law, Maria De Marco, grilling lemon chicken for the pope for lunch Friday at his temporary home on East 72nd Street.

“It’s like touching the sky,” Alba said of feeding Francis, a fellow Argentine native.

The pope needed a special diet — chicken, no spices, no salt. Secrecy was essential, he was told, “for the holy man’s safety.”

The grill — specially designed for Argentinian-style cooking, in which the meat is raised and lowered repeatedly over three hours — had to be disassembled to fit down a spiral staircase at the home.

And police sniffer dogs had to approve of everything.

“They said if the dogs sit down, there’s a problem,” Alba recalled.

After the meal, Francis invited a nervous Alba to his side, telling him in Spanish, “The pope doesn’t bite you!”